Question

Given a matrix A, what is A^-1?

Answer 1

@zepdrix

Answer 2

what is our determinant? i recall a rule if we have a row or col of zeros

Answer 3

\(\large {
A=
\begin{bmatrix}
a&b\\c&d
\end{bmatrix}\qquad A^{-1}=\cfrac{1}{a\cdot d-c\cdot b}
\begin{bmatrix}
d&-b\\-c&a
\end{bmatrix}
}\)

Answer 4

determinant=0

Answer 5

if |A|=0,then \[A ^{-1}~does~\not~exist.\]

Answer 6

awesome, thanks!

Answer 7

could you help me with another?

Answer 8

Which is the component form of the vector shown?

a) (-6, 7)
b) (-2, -5)
c) (6, -7)
d) (-5, -2)

Answer 9

\[A ^{-1}=\frac{ 1 }{ \left| A \right| }~adjoint~A\]

Answer 10

so the answer is "does not exist.

Answer 11

correct.

Answer 12

Vector DE
\[=\left( 2-(-4) \right)i+\left( -6-1 \right)j=6~i-7~j\]

Answer 13

@zepdrix

Answer 14

@Loser66 can you help?

Answer 15

what? 0_o

Answer 16

I need helpppp

Answer 17

with the vector thing? :U

Answer 18

surj gave you the answer :U